There's "having nukes" and there's "using nukes".

https://m.youtube.com/watch?v=QgkUVIj3KWY

The trouble with a regime like Iran is that they are a death cult. The price the put on human life (their own people as much as anyone else) is low, and they're all for martyrdom. With Iran, you cannot assume it's a just a deterrent in a cold war. You have to assume an increased likelihood that they will actually use them.